1. Technical Field
The present invention relates generally to probe card, and more particularly to a probe card which is capable of transmitting high-frequency signals.
2. Description of Related Art
Probe cards are applied as transmission interfaces between a tester and a device under test (DUT) to transmit test signals and power signals, which is a widely used method for testing if every electronic component of the DUT is electrically connected correctly.
However, with the advancement of digital technology, the operating speed and the signal throughput of electronic devices are increasing, which make the frequencies of test signals generated by processors of the tester insufficient to satisfy the demand to test such electronic devices. Therefore, in order to solve this problem, the DUT may be utilized to generate high-frequency signals which meet test requirement, and those signals are then transmitted back to the DUT again via probe cards.
Nevertheless, on a conventional probe card, there would be a slight inductance between a wire and a pin while the probe card is transmitting signals, and due to electrical field effects, resistance would increase with higher frequencies of signals transmitted. As a result, the circuit structure of the conventional probe card becomes a low-pass circuit. As shown in FIG. 1 and FIG. 2, the low-pass circuit obstructs high-frequency signals from passing therethrough, and therefore test signals may be not easily recognized by the DUT, which may lead to misjudgment during test procedures. To improve the aforementioned situation, pins with lower inductance would be needed, or the circuit structure would have to be re-designed. These methods would either cost more or increase the complexity of circuits, which is detrimental for maintenance and development in the future.